Any cellphone after 2005.
Having a seperate device is nice for battery life. I listen to music constantly, so I know my phone would die two or three times as quickly, if I used it for music.
I like Apple's iPods. I have a simple iPod nano 8GB, friend sold it to me. It has served me well for 3 years, battery still lasts very long, excellent sound quality. The interface is great, and it's a very discrete device.
With all that said, I hate Apple, and the only reason I got it is because a friend sold it to me. They make good devices, but their prices are obscene and so is the company as a whole. Do not buy their stuff unless you can get it used and cheap.
On the subject of bad DACs in music players, iPods are praised for having great quality in that regard. Really though, most modern DACs, even in cheap devices, are perfectly fine for most headphone use. Unless you plan to connect your device to a hi-fi system by jack, you shouldn't have a problem.